It's too early to tell whether debris found on Réunion Island Wednesday could be part of the wreckage of Malaysia Airlines Flight MH370, which disappeared off the coast of Malaysia in March 2014, and whose mysterious fate has been the source of much speculation and consternation.

"People are getting ahead of themselves over this," said Eric Chesneau, an officer with the air transport police of the French Indian Ocean territory, in response to speculation on social media. "It is more than likely plane debris, [but] we don't know what exact part it may be."

Speculation was rife online Wednesday that debris that washed up in the town of Saint-André on the northeast coast of the French island, about 1,000 km east of Madagascar, was part of a wing of a Boeing 777 jet, the same kind of plane as MH370, but no one has officially confirmed that detail.

An unnamed U.S. official told The Associated Press that air safety investigators, including one from Boeing, have a "high degree of confidence" that, based on the photos, the piece of debris is a wing component unique to the Boeing 777.

Local radio station RTL Réunion reported that a two-metre long piece of plane debris was found by a local group that clears trails along the coastline. The debris had some kind of identifying code on it, the station reported, which might make it easier to identify, and people who saw it up close said it was covered with shells.

"We've received some pictures of the item, and we are having them assessed by the manufacturers as to what they may be," Joe Hattley, a spokesman for the Australian Transport Safety Bureau, which is leading the search for MH370,  told Australian Associated Press (AAP).

"The French authorities have it secured. We'll work with the French. First, we need to determine what the item is and whether it is part of a Boeing 777 and then if it is part of MH370."

Reuters reported that France's air crash investigation agency, Bureau d'Enquêtes et d'Analyses, is studying the debris.

Hatley told AAP that investigators will be looking for a part number and a serial number that could possibly be matched to a specific aircraft frame.

"Similar parts on different planes would have a number," he told AAP. "And you'd have a serial number, a specific number to that particular component."

Theories on source of debris

The most recent crash that occurred near Réunion happened on May 5, 2006, when a twin-engine plane crashed into the ocean across from the Pierrefonds airport on the southwest coast of the island, RTL said. 

MH370 search

Debris that likely came from a plane was found on Reunion Island, west of the large area in the southern Indian Ocean where authorities have been searching for MH370. (CBC)

Another possible source of the debris could be the 2009 crash of Yemenia Flight 626, which went down on its approach to Comoros, an archipelago off the northwest coast of Madagascar.

Gérard Feldzer, a former Air France pilot, told the Libération newspaper that it's impossible to say anything conclusive based on the photos and that analyses will have to be done on the metal and paint to determine the age and other details of the aircraft it came from.

If the debris were to be traced to MH370, it would be the first sign of the passenger aircraft since it disappeared in March 2014. 

Malaysia Plane

It's been almost a year and a half since MH370 disappeared somewhere in the southern Indian Ocean and not a trace of it has been spotted to date despite millions of dollars having been spent on a massive, multi-nation search. (The Associated Press)

Exactly what happened to MH370 has never been established, and no trace of the wreckage has been found despite millions of dollars spent searching for the plane.

Flight MH370 took off from Kuala Lumpur, Malaysia, on March 8, 2014, at 12:41 a.m. local time headed for Beijing. Less than a half hour into the flight, air-traffic control on the ground lost contact with the jet, and less than two hours into the flight, it disappeared from military radar, although it continued to send data to a satellite until 8:11 a.m. Malaysia time. 

The plane was carrying 227 passengers, most of whom were Chinese, and 12 crew.

Bluefin-21 Malaysia Airlines flight MH370

Several nations have contributed ships and specialized equipment to help locate the wreckage of MH370. (Peter D. Blair/Reuters, handout)

When it disappeared from radar, it was heading west across the Strait of Malacca — the opposite direction from where it was supposed to be flying, leading experts to conclude that it veered from its intended flight path, turned around and flew back across the Malaysian peninsula toward the Indian Ocean.

No closure for relatives of victims

Authorities initially focused the search for the plane on the South China Sea, the Straits of Malacca and the Andaman Sea but later shifted their attention much farther south to the remote southern Indian Ocean after the satellite telecommunications company Inmarsat released data that suggested that's where the plane went down.

The southern Indian Ocean search has been co-ordinated primarily by Australia, although Malaysia and China have also contributed funds and resources, and several other countries have lent expertise and equipment.

MALAYSIA-AIRLINES/

Relatives of those who were aboard the flight have not been able to get closure and know almost nothing about how their loved ones died. (Jason Lee/Reuters)

To date, the search has cost more than $100 million and extended across tens of thousands of square kilometres.

This spring, the search area was expanded beyond the original 60,000 square kilometres to enable up to 120,000 square kilometres to be searched. More than 55,000 square kilometres of the sea floor have been searched so far, according to the Australian Transport Safety Bureau, and the search will continue through the winter months in the Southern Hemisphere.

MH370 search area

A map of the expanded MH370 search area in the southern Indian Ocean. Yellow sections indicate areas already surveyed. The potential search area now extends to 120,000 sq. km. (Australian Transport Safety Bureau)

In January of this year, the disappearance of the jet was officially declared an accident and all people on board were presumed dead in order to facilitate compensation for the victims' families.

A comprehensive report into the disappearance found no significant anomalies in the flight, except that the battery of the locator beacon for the plane's data recorder had expired more than a year before the jet vanished.

That still does not explain what caused the plane to veer so off course in what has become aviation's biggest mystery that continues to confound experts and investigators alike. At the same time, the relatives of the dead have got no closure, and many still believe that their loved ones may be alive amid a host of conspiracy theories including one that the plane was hijacked and landed somewhere safely.

The case of the missing jet has prompted many comparisons with Air France Flight 447, which crashed en route to Paris from Rio de Janiero in May 2009 with 228 people on board and wasn't found until two years later, but the key difference in that case was that searchers found some debris and the bodies of several victims of the crash days after the plane went down, helping narrow the search.

With files from Reuters and The Associated Press